In the present specification, an organic electronic device is an electronic device using an organic semiconductor material, and requires hole and/or electron exchanges between an electrode and the organic semiconductor material. An organic electronic device may be categorized into two main groups depending on an operation principle. First is an electronic device in which excitons form in an organic material layer by the photons brought into the device from an external light source, these excitons are separated into electrons and holes, and these electrons and holes are used as a current source (voltage source) by each of these being transferred to different electrodes. Second is an electronic device in which holes and/or electrons are injected to an organic semiconductor material layer that forms an interface with an electrode by applying a voltage or a current to two or more electrodes, and the device is operated by the injected electrons and holes.
Examples of an organic electronic device include an organic solar cell, an organic light emitting device, an organic photo conductor (OPC), an organic transistor and the like, and these all need an electron/hole injection material, an electron/hole extraction material, an electron/hole transfer material or a light emitting material for the driving of the device. Hereinafter, an organic solar cell will be described in detail mostly, however, in the organic electronic devices described above, the electron/hole injection material, the electron/hole extraction material, the electron/hole transfer material or the light emitting material is all used under similar principles.
A solar cell is a battery changing electric energy directly from sunlight, and studies thereon have been actively progressed since it is a clean alternative energy source for resolving fossil energy depletion and global environmental problems caused by the use thereof. Herein, the solar cell means a battery producing current-voltage using a photovoltaic effect producing electrons and holes by absorbing light energy from sunlight.
A solar cell is a device capable of directly converting solar energy to electric energy by applying a photovoltaic effect. Solar cells are divided into inorganic solar cells and organic solar cells depending on the materials forming a thin film.
Numerous researches have been ongoing for increasing power conversion efficiency through changes in various layers and electrodes obtained by solar cell designs.